I put a very thick, shag rug under my desk, and my old, thin plastic chair mat was cracked and at end of life. My chair wheels kept sinking through the cracks. I bought this new one after scouring the sites and not finding too many that claimed to work on thick carpet. It's working great so far. It feels thicker than my old mat, but not by a ton. Somehow though, the quality is just so much better. It's letting my chair glide with ease. People are not exaggerating though when they say it's hard too flatten when you first get it. I did manage it myself, but it was a workout. I waited the 24+ hours, and then I slowly added weights. After another day it was ready. Between dumbbells and 10 lb plates, I used over 100 lbs.